The pgInstaller distribution of PostgreSQL for Windows is not being maintained
for PostgreSQL 8.4 and above.

PostgreSQL 8.4 'one-click' installers for Windows can be downloaded from:

<a href="http://www.enterprisedb.com/products/pgdownload.do">http://www.enterprisedb.com/products/pgdownload.do</a>

A ZIP archive with just the binaries and no installer can be downloaded from:

<a href="http://www.enterprisedb.com/products/pgbindownload.do">http://www.enterprisedb.com/products/pgbindownload.do</a>